Electron discharge device



March 24, 1942 H. w. WEINHART 2,277,423

ELECTRON DISCHARGE DEVICE Filed May 17, 1941 WM@ M ATTORNEY PatentedMar. 24, 1942 2,277,423 ELECTRON DISCHARGE DEVICE Howard W. Weinhart,Elizabeth, N. J., assigner to Bell Telephone Laboratories, Incorporated,New York, N. Y., a corporation of New York Application May 17, 1941,Serial No. 393,922

Claims.

This invention relates to electronic discharge devices and moreparticularly to devices having multicontrol elements for electronicswitching application in the electric and communication arts.

In the copending application of A. M. Skellett,

Serial No. 393,921, filed May 17, 1941, a multicontrol electronicdischarge device is disclosed in which a plurality of annular flatcontrol elements are mounted about a central cathode and an anodecooperates with these electrodes in which each control element isprovided with an individual conductor sealed through the vessel toeffect the selective switching operation of the device.

In certain aspects of this device it is desirable, from a productionstandpoint, to provide the multiple kconductors for the control elementin an annular rim seal near one end of the vessel and to couple theseconductors to the various control elements. During operation theelectrodes and their supporting parts are necessarily subjected todistortion stresses which might endanger the static and dynamiccharacteristics of the device. This is particularly evident inconnection with the disc-like control elements which determine thetransconductance characteristics of the device.

An object of the invention is toY overcome distortion of the controlelements of multiswitching electronic discharge devices.

Another object of the invention is to improve the mechanical andelectrical efficiency of multigrid discharge devices.

A further object of the invention is to facilitate the fabrication ofthe multicontrol elements in a compact unit readily supported in anenclosing vessel.

These and other objects of the invention are attained in accordance withthis invention in one aspect thereof in which a plurality of annulardisc-like control elements are interposed between a central cathode anda cooperating anode and mounted in a unitary assembly in which theelements are insulatingly stacked in coaxial alignment about the cathodeand mounted between insulating end spacer discs which are clampedtogether to form a rigid unit. This unit slidably lits into acylindrical vessel and the unit is supported by a pair of hangers sealedin the top of the vessel.

A rim seal incorporating the multiconductors for the control elements islocated below the unit and the thin disc-like control elements are con-Wires which are connected to the conductors and slidably extend throughthe lower spacer disc.

The rigidity of the unit insures protection for the elemental parts ofthe assembly so that the unit as a whole contracts and expands uniform-1y. Since the coupling wires are flexible and slidably mounted withrespectto the unit, any distortion which is present is expended in thewires which can absorb the stresses without producing anypermanent settherein. Consequently, any harmful distortion to the control elements isgreatly dissipated before reaching them so that the device exhibitsstable characteristics throughout its operating life vand the functionaloperation is rendered more constant.

A feature of the invention relates to the segregation of the conductorsfor the cathode and anode in an outwardly extending stem distinct fromthe annular seal involving the conductors of the control elements of thedevice.

Another feature of the invention relates to the mounting assembly of theunit in which the stacked control elements and the other cooperatingelectrodes are rigidly held in position between end spacer discs byenlarging the ends of the upright supports ofthe stacked unit, theenlarged heads of the supports at the top of the unit being anchored tothe hangers in the vessel to relieve the weight of the unit from theflexible connector wires of the control elements.

These and other features of the invention will be more clearlyunderstood from the following detailed description taken in connectionwith the accompanying drawing in which:`

Fig. l is a perspective view of the device embodying the features ofthis invention with a part of the vessel broken away to show the variousdetails of the assembly;

Fig. 2 shows the device in elevation with the vessel shown in crosssection and various details broken away or shown in section toillustrate the relationship of the elemental parts of the assembly;

Fig. 3 is a cross-sectional view on the line 3-3 of Fig. 2 showing theconfiguration lof the electrodes and the relationship of the connectorwires with respect to the control elements; and

Fig. 4 is a cross-sectional view on the line 4-4 of Fig. 2 showing thedistribution of the connector wires for the control elements about theperiphery of the lower disc spacer of the unit.

Referring to Figs. 1 and 2, the device of this invention comprises acylindrical enclosing vesnected to the conductors by yieldable orflexible sel l0 and a cup-shaped stem H of glass or similar insulatingmaterial, the stem having an outwardly extending sealed press portion I2in which four parallel wires I3 are sealed to provide external terminalconnections for the input and output electrodes of the device. The stemII is also provided with a circular flange I4 which abuts against asimilar ilange I5 on the cylindrical vessel I to form an annular rimseal IB for a plurality of radial conductors II which extend through theseal for providing multiple terminal conductors for the control elementsof the device. closed by a dome portion I8 having a central sealing tipI9 and a pair of anchoring projections and 2I in which metallic hangers22 and 23 are embedded and extend diagonally within the vessel.

The unitary electrode assembly, enclosed'within the cylindrical vessel Iis suspended and substantially supported by the hanger arms 22 and 23 atthe top of the vessel and comprises a pair of spaced discs 24 and 25 ofsuitable insulating material, such as mica or lava. The discs are ofsuch diameter as to slidably engage the inner Wall of the cylindricalvessel Ill, and are held on opposite ends of the electrode unit byparallel upright rods 2G and 21 which extend through apertures therein.These rods are welded to the arms 22 and 23 at the top of the vessel torigidly support the unit therein. A central tubular cathode 28 ismounted axially between the discs and is provided with an electronemissive coating 29, such as alkaline earth oxides of barium andstrontium. The cathode is also provided with an internal heater havingterminations which are connected to conducting Wires 3Q extending to twoof the lead-in conductors I3 in the stem II, the cathode being connectedto another wire 3|, which is also connected to a terminal leadin wireI3. An anode or output electrode cooperates with the cathode and is inthe form of arcuate rectangular sections 32 and 33 extendinglongitudinally on opposite sides of the cathode between the end spacerdiscs. The sections are supported by short wires 34 and 35 arranged inpairs at the top and bottom thereof, and extending through the endspacer discs 2d and 25. The short wires 34, extending through the topinsulating disc, being bridged by strap wires 35 and one of the shortwires 35 in the lower insulating spacer 25 being connected to aconductor 31 which is coupled to the remaining leading-in terminal I3 inthe stem.

The upright supports 25 and 21 extending between the end insulatingspacers are surrounded by a long sleeve 38 of suitable insulatingmaterial, such as aluminum oxide, the sleeve being in abutting relationto the end disc spacers 24 and 25. A plurality of angular flat controlVelements or grids 39-coaxially surround the cathode 28 and are equallyspaced in longitudinal alignment from the cathode and the anode sections32 and 33, along the whole length thereof. This is accomplished byproviding integral arm extensions on opposite sides of the centralannular portion 39, the arm extension 43 on one side being short andprovided with an aperture to slidably t around the insulating sleeve 38on the upright support 2'I and the other arm extension 4I beingrelatively long and provided with an aperture whose diameter issuiiicient to pass over the sleeve 38 on the upright support 26. Theannular control elements are equally spaced on the upright supports byinsulating collars 42 so that the control elements are accuratelystacked The top of the cylindrical vessel I0 is in rigid position on theupright supports, the long arms of the control elements extendingalternately on opposite sides of the assembly to provide suitablespacing between the projecting arms of the elements to increase theinsulation resistance between adjacent control elements. The wholeassembly including the stacked control elements, the cathode and theanode and the end spacer discs, is rigidly clamped together by pinchingor crimping the sides of the upright rods 26 and 27 at opposite ends ofthe unit to provide wedging ears 43 and 44 which rigidly lock the endspacer discs against the electrode assembly and maintain all theelectrodes in accurate spacial relation.

In order to compensate for expansion of the electrode elements and theassembly and also to prevent distortion of the flat control elements andthe radial leading-in conductors I'I in the ring seal I6 of the vessel,the coupling between the control velements and the conductors isaccomplished by small diameter flexible connecting wires, such as 45,which slidably pass through the lower insulating spacer disc 25 andextend from the leading-in conductors I'I to the respective controlelements. As shown in the drawing, there are twenty control elementsstacked around the cathode and a corresponding number of terminalconductors I'I in the rim seal. The connector wires 45 are equallydistributed in a circular boundary about the electrode unit, each wirebeing provided with a long upright portion which slidably extendsthrough the lower insulating disc 25 and is welded at the lower end to acorresponding radial conductor arranged at right angles thereto andprovided adjacent the control element with a bent portion 46, adjacentwires having their angular bent portions arranged in successive stepsand curved toward the long arms 4I of the control elements as shown inFig. 3. This arrangement materially prevents distortion of the thin,flat control elements since any expansion and contraction of the unit iscompensated by the flexibility of the connector wires 45 which areslidable in the lower spacer disc 25 and are suiciently distributed withrespect to adjacent wires so that any ilexing or strain placed thereonwill not be communicated to the control elements or the respectiveleading-in conductors.

Furthermore, the substantial support of the electrode unit in the vesselby means of the hanger arms 22 and 23 and the side support of the unitby the contact of the spacer discs with the inner wall of the vessel,relieves strain on the leading-in conductors of the various electrodesand the seals thereof and since the compensation of expansion andcontraction is provided by the ilexible connector wires, it is evidentthat the multicontrol elements and their electrical characteristics aremaintained uniform regardless of the temperature conditions inherent inthe operation of the device.

While the invention has been disclosed with respect to a particularembodiment thereof, it is, of course, understood that variousmodications may be made in the detailed assembly without departing fromthe scope of this invention as defined in the appended claims.

What is claimed is:

1. An electron discharge device comprising an enclosing vessel, anelectrode unit mounted Within said vessel, said unit-including a centralcathode, a plurality of apertured disc control elements coaxially`lsurrounding said cathode,

spacer discs at opposite ends of said unit, and a plurality of membersfor insulatingly supporting said control elements in longitudinal spacedrelation along the length of said cathode between said discs, saidmembers having means clamping said elements and spacer discs into aunitary assembly.

2. An electron discharge device comprising an enclosing vessel, anelectrode unit mounted within said vessel, said unit including a centralcathode, spacer discs at opposite ends of said cathode, a pair ofupright supports extending parallel to said cathode and through saidspacer discs, and a plurality of apertured disc control elementsinsulatingly stacked on said supports and surrounding said cathode, saidsupports being enlarged external to said spacer discs to rigidly clampsaid discs and elements into a unitary assembly,

3. An electron discharge device comprising an enclosing vessel, anelectrode unit mounted within said vessel, said unit including a centralcathode, spacer discs at opposite ends of said cathode, a pair ofupright supports extending parallel to said cathode and through saidspacer discs, and a plurality of apertured disc control elementsinsulatingly stacked on said supports and surrounding said cathode, saidsupports being provided with integral ears external to said discs toperform a clamping action against said discs at opposite ends of saidunit.

4. An electron discharge device comprising an enclosing vessel, anelectrode mount within said vessel including a cathode and an anode, aninsulating spacer disc at each end of said mount, a pair of uprightsupports extending between said discs parallel to said cathode andanode, a plurality of iat annular control elements insulatingly stackedon said supports and coaxially spaced between said cathode and saidanode, said support having enlargements on the ends clamping said spacerdiscs and stacked elements into a rigid assembly, and a pair of hangerarms at one end of said vessel secured to said supports to hold saidmount in suspension.

5. An electron discharge device comprising a cylindrical enclosingvessel, an electrode unit within said vessel including a cathode, ananode, and a plurality of apertured disc-like control elementssurrounding said cathode and mounted in spaced relation to said anode, aspacer disc at each end of said cathode, means extending through saiddiscs for supporting said elements, a plurality of conductors sealed insaid vessel for said elements, and a pair of hanger arms sealed in thetop of said vessel and secured to said means for supporting said unit.

6. An electron discharge device comprising a cylindrical enclosingvessel, an electrode unit within said vessel, including a cathode, ananode, and a plurality of apertured disc-like control elementssurrounding said cathode and mounted in spaced relation to said anode, aspacer disc at each end of said cathode, means extending through saiddiscs for supporting said elements, a plurality of conductors sealed insaid vessel electrode unit mounted within said vessel including acentral tubular cathode, a plurality of apertured disc elementssurrounding said cathode having perforated side extensions, a pluralityof stacked insulating collars interposed between said elements inalignment with said perforated extensions, end spacer membersterminating said unit and engaging the inner wall of said vessel,supports extending through said collars, elements and spacer members andprovided with clamping portions to lock the stacked parts into a rigidunit, and an individual terminal connection for each of said elementsextending through a rim seal of said vessel, said connection passingslidably through an end spacer member between said element and saidseal.

- 8. An electron discharge device comprising an enclosing vessel, anelectrode mount within said vessel supported from the top thereofincluding a plurality of at metallic elements arranged in stacked spacerelation, a plurality of lead-in conductors radially sealed in saidvessel below said mount, and a flexible wire connector extending betweeneach of said elements and a corresponding conductor, each wire beingslidably movable with respect to said mount to prevent distortion insaid element and said conductor.

9. An electron discharge device comprising an enclosing vessel, anelectrode mount within said vessel supported from the top thereofincluding a plurality of flat metallic elements arranged in stackedspace relation, a plurality of lead-in conductors radially sealed insaid vessel below said mount, and a flexible wire connector extendingbetween each of said elements and a corresponding conductor, each wirehaving a long portion intersecting its respective conductor and a curvedbent portion directed toward and attached to the respective metallicelement.

10. An electron discharge device comprising an enclosing vessel having aflanged rim portion and an outwardly extending stem, a plurality ofconductors radially sealed in said rim portion, other conductors sealedin said stem and extending parallel to the aXis of said vessel, anelectrode mount within said vessel including a cathode, an anode, aplurality of annular flat control elements insulatingly stacked betweensaid cathode and said anode, and end spacer discs in contact with saidvessel, a pair of hanger members anchored in said vessel and supportingsaidmount, connections from said cathode and anode to said conductors insaid stem, and a plurality of exible wires coupled to said elements andsaid conductors radially sealed in said rim portion, said wires beingdistributed within the boundary of one of said spacer discs and slidablymovable therein.

HOWARD W. WEINHART.

